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Objective: The sternoclavicular joint (SCJ) is important for shoulder motion. The innervation of SCJ is a key to discuss its proprioception and motor control of the pectoral girdle. However, little is known about innervation of the SCJ and possible cause for the disorder of SCJ proprioception. The aim of this study was to clarify the innervation of SCJ and to provide anatomical basis for understanding the proprioception of SCJ contributing to the shoulder motion. Methods: Six sides of nerve branches to the SCJs were dissected and observed under stereomicroscope, after maceration in trypsin solution to facilitate removing muscle and connective tissue, and pursuing fine nerve branches to the SCJ. The protocol of this study was approved by institutions of the authors. Results: In all six sides, nerve branches from the medial supraclavicular nerve (MSN) went medially along the clavicle and reached the anterior and/or superolateral part of the articular capsule of SCJ. In four sides, nerve branches from the lateral pectoral nerve (LPN) went medially between the clavicle and first rib, and reached the inferior part of the articular capsule of the SCJ. In other two sides, a similar branch from the LPN did not reach the SCJ but ended at the periosteum of manubrium and/or perichondrium of first costal cartilage. Conclusion: The SCJ was innervated by nerve branches from the MSN and LPN, or MSN only. Findings of this study suggest that the proprioception of SCJ could be disordered by injury of the clavicle or upper pectoral region. [ABSTRACT FROM AUTHOR]